Patients with chronic kidney disease (CKD) develop anemia due primarily to deficient production of erythropoeitin (EPO). Administration of EPO to patients with end-stage renal disease (ESRD), stimulates erythropoiesis and often leads to functional iron deficiency. Furthermore, iron losses are high, particularly in the hemodialysis patient. Patients are frequently non-compliant with oral iron supplements due to associated gastrointestinal side-effects. Oral iron supplements frequently fail to maintain adequate iron stores in EPO-treated hemodialysis patients. The use of i.v. iron has been shown to increase hemoglobin, and may therefore improve quality of life, and reduce morbidity and mortality in uremic patients. However, life-threatening/serious acute reactions to i.v. iron have been reported. Recent evidence suggests that i.v. iron leads to oxidative stress in ESRD. Oxidative stress, universally present in ESRD, has been implicated as one of the causes of atherosclerosis and resulting high morbidity and mortality from coronary artery disease, strokes and gangrene in these patients. To explore delivery of iron via the dialysate, ferric pyrophosphate (FePPi), the most stable and nontoxic of all monomeric iron salts has been selected. The present study will test the safety and efficacy of FePPi delivery via the dialysate in preventing iron deficiency, in chronic hemodialysis patients. The specific aims of this study are as follows: 1 ) To determine the efficacy of hemodialysis solutions containing ferric pyrophosphate in preventing the development of iron deficiency, compared with the conventional hemodialysis solutions. 2) To determine the safety of hemodialysis solutions containing ferric pyrophosphate, compared with the conventional hemodialysis solutions, by monitoring adverse reactions manifesting clinically or on laboratory testing. 3) To study catalytically active iron on markers of inflammation and oxidative stress 4) To study the effect of dialysate iron on dialyzer reuse.